The concept of a “valid” argument is that IF all the premises are true, then the conclusion MUST be true.
A “sound” argument is a valid argument that HAS true premises.
It seems to me that the sign above is a valid argument, If A, then B. If B, then C — therefore if A then C — BUT, I do question the truth of the premisies —
So, this sign moves us from logic to Intro to philosophy and/or Ethics, because the truth of the premises is the sort of question we tackle there.